If the Romans distinguished themselves in anything, it was in the capacity to take engineering to levels never before seen in antiquity. As in many other aspects of their society they were able to learn from neighbours or assimilated peoples and improve their ideas and knowledge by pushing them to the limit until they touch the exquisiteness. They invented a lot but perfected much more.
It is only necessary to observe the titanic network of roads with which they communicated the most distant territories of the empire with the capital to understand it: from the north of Britannia to the Persian Gulf, passing through the African deserts to the borders of Germania. And in its splendor the main imperial roads consisted of more than 100,000 kilometers and even the secondary roads were made with such quality that not even inclement weather prevented the to and fro of merchants and armies: they deforested, flattened, developed different layers with diverse materials and techniques until finishing stone by stone, slab to slab fitted to perfection and they knew how to give the subtle inclination necessary to drain down the sides and avoid the interruption of the communications that were vital for them. Anyway, it should be noted that a Good number of roads, especially the secondary ones, did not have a paved surface, rather it used to be composed of fine granular materials on thick stones, which allowed good water filtration and good circulation.
What to say also of the magnificent bridges that saved impossible orographies as the bridge of Alcantara near Augusta Emerita in Hispania or the bridge of Trajan on the Danube in Dacia, work of the legendary Apollodorus of Damascus and of which there are still vestiges.
In military engineering they were able to raise the famous Hadrian’s Wall stone by stone, the Limes Britannicus, 3 metres thick and almost 5 metres high from coast to coast along 117 kilometres with 14 main fortifications and 80 minor fortifications to shelter the border of the Picts, or what to say of the less known but not less important Limes Germanicus built mainly in wood, except for some sections and important fortifications, along 568 kilometres following the Rhine and the Danube to protect the northern border of the barbarian raids. They erected 60 main fortifications and 900 watchtowers capable of communicating with each other and warning of any open breach at the border in time.
The military knew how to take advantage of civil engineering, using these magnificent communication channels and bridges to move the legions around in such a short time that the enemies often did not believe what their eyes saw when they faced legions perfectly formed hoping them still many days away. Thanks to the communication channels and a strict preparation: let us not forget that a legion advancing by forced marches was able to travel enormous distances at an impressive speed, as when Julius Caesar stood with his legions in southern Belgium from the Cisalpine Gaul crossing the Alps in record time. Likewise military engineers were able to build temporary bridges to cross any river as large as it was: the Rhine and the Danube witnessed it: Caesar himself taught it to the Swabians in the first and Trajan to the Dacians in the second. So important was this aspect for the gearing of the best army in history until the invention of gunpowder, that a unit of skilled engineers known as fabri was in charge of satisfying any request from the commands, no matter how difficult and arduous the task was. For them it was a cinch to organize and build a camp or castra for a full legion before nightfall with soldiers who had spent the day sometimes marching through unknown territory. Fosse, terreplain and wall towered over a new domain although it was only for one night to repeat the same operation in another place the next day. Even today remains of these buildings are still found in territories as far away from the old borders as in the current Ireland, Czech Republic, Holland, Germany, Egypt and Middle East countries.
About the military machinery we will talk in more detail in military sections.
In civil engineering, apart from roads and bridges, water management deserves a special and outstanding mention. Without the precious liquid and its constant flow to all enclaves with a minimum population, one can not understand the prosperity throughout the Roman nation. Nowadays in many places of the world they have not solved this basic problem for the human development and the Romans already more than 2,000 years ago understood the fundamental thing that was to guarantee the supply to the cities for the good functioning of their societies. A well-known example we have in Gaul with the aqueduct of Nimes and its splendid pont du Gard as a symbolic icon of a magnificent work of 50 kilometres, of sometimes sinuous route that bores rocks and caves and builds bridges to maintain a tiny and constant inclination that allowed the circulation of water from the source to the municipal deposits, with only 12 metres of gradient from start to finish. They did this in Nimes and throughout all their domains, whether they were the multiple aqueducts that satisfied the million inhabitants of Rome or one unknown in recondite lands. Apart from Nimes, we find other precious remains in the province of Hispania, for which neither the aqueduct of Segovia nor the pont del diable in Tarragona seems to pass the time. On many occasions they used dams to dispose of better water reserves. Without going any further, up to 72 of a certain size have been documented in present-day Spain, such as those still able to be visited of Proserpina and the Cornalvo dam in Merida.
Remarkable was the development of mining, leaving samples such as Rio Tinto in Huelva and Las Medulas in Leon. Both in the main mining province of the empire: Hispania, cited in this field with reverence for Pliny, Mela and the Greek Strabo for their great importance. The use of hydraulic power was raised to the category of art and multiple remains demonstrate the colossal magnitude of the mining operations that mainly focused on the extraction of silver, gold, iron, copper and lead. Other prominent provinces were Gaul, Dacia, Cyprus, Egypt and Britannia, and only together could compete in volume and wealth with those of Hispania. With these raw materials at their disposal they developed advanced metallurgy techniques to get the most out of them.
They carried out important engineering works in all the fields: sewers that allowed improvements in the levels of health of the population never seen before in nuclei of thousands, tens of thousands and sometimes hundreds of thousands of inhabitants, like those of Rome, where the most ancient: the Cloaca Maxima, dated in the 6th century BC in the legendary times of the ancient kings, it is still in operation today and its exit is perfectly visible on the banks of the Tiber. Many European cities of all sizes and conditions continue to make use of these old civil works without their inhabitants being aware of them. Roman engineers also developed the air conditioning of spaces and waters, both for public baths and for villas or palaces of wealthy personalities that could afford it: known as hypocaust, they devised an air heating system with pipes that traversed walls and floors. For example, the Baths of Caracalla in Rome where hundreds of slaves kept an internal and an external furnace in operation, for the enjoyment and delight of up to 2,000 people who cleaned, relaxed and closed deals between real pools of all temperatures adorned with mosaics both on the floor and on the ceiling, marbles, sculptures and all kinds of rich ornaments that making the imagination fly makes us think how well the average citizen could benefit from the wealth and power of Rome. They were also masters in the construction of domes or vaults, reaching the limits of physics in the pantheon of Agrippa in Rome and in the basilica of Hagia Sophia in Constantinople. Finally, they are the inventors of the best cement on record, capable of resisting under water for two millennia when the best cements of today (such as Portland) are unable to survive a single century. Thanks to this they were able to devise works of the magnitude of the Colosseum of Rome and the aforementioned pantheon of Agrippa. It is a pity that at some point in history the techniques for its elaboration have been lost.
In all these works the engineers used improved machinery or of new invention that promoted a new and better world. Special mention should be made of the Archimedes’ screw used to raise water or dry land flooded by it, the surveying instruments that allowed the best roads and aqueducts, and all kinds of cranes, pulleys and hoists that allowed moving tons of stone in multiple engineering works or extravagances such as making a lion appear under the arena of an amphitheatre in the middle of a gladiatorial fight.
The reference figure in Roman engineering is VITRUVIUS, author of the oldest work on this subject and the only one of antiquity that has come to this day: De architectura, used even in the Middle Ages and after its full rediscovery by Petrarch is considered that laid the foundations of Renaissance architecture. It consists of 10 books dealing among other things about machinery, buildings, materials, hydraulics and colours. His work encompasses diverse disciplines: engineering, architecture, crafts, landscape and art. He was the architect of Caesar in his youth and dedicated his treatise to the later Emperor Augustus.
Other prominent characters are:
APOLLODORUS of Damascus, creator of legendary works like the Trajan column, of the magnificent and considered impossible bridge over the Danube in the Iron Gates, fundamental for Trajan to submit all of Dacia. Other outstanding works are the baths of Trajan, the Trajan forum (with the Basilica Ulpia and the great market of Trajan), the port of Ostia, and the triumphal arches of Ancona and Benevento among others. Finally, it should be noted that the pantheon of Agrippa of Hadrian’s time is attributed to him, for being contemporary and being a work of a sublime technique for the elevation of the heaviest vault in history until then. He was architect and engineer of several emperors, but mainly he was the executor of the dreams of Trajan.
CAIUS SERGIUS ORATA, the inventor of the hypocaust, an underground heating system widely used in therms and in the homes of wealthy citizens.
In this Dynamic Map we can see the mines exploited by the Roman Empire
Author: Eduardo Ortiz Pardina